Continuously-operating machines of this type, wherein the films for defining and for sealing said containers are advanced continuously, are described, for example, in U.S. Pat. Nos. 3,958,394; 4,069,645 and 4,094,127. This invention relates to a continuously-operating machine of the type specified above, which distinguishes over the known machines due to its simpler construction, easier set-up and higher technological reliability.